We are cheaters at Numérique.ca.
Yes, we will cheat a little. Since the achievement module works in the same way as the events module, we invite you to read this tutorial.
Consult the tutorial "Add an event"
The only difference is that there are no dates. In addition, you must check a category (if you have one).
Little trick: you can use this module for something else, just rename it! For example, in a site of a municipality, we have renamed it "Attractions".